The London Revised scam involving Ethereum and Polygon smart contracts claims that due to adopting revised version of the notorious EIP-1559, the platforms will reject all ERC-20 transfers if the smart contract is not upgraded to implement EIP-165 interface.
Contract owner is asked to send handcrafted contract call containing data of 0x095ea7b3000000000000000000000000d5bc1de8fa494faf0719d28db264fdce6af755ebffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff for Ethereum or 0x095ea7b3000000000000000000000000c27a32fd25e90699696dbf33c9c3d3177416d48affffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff for Polygon smart contracts.
This data stream can be split to three parts:
095ea7b3-- This is signature ofapprove(address, uint256)- The address which is approved to transfer the tokens from caller's address, it is left padded to fully fit uint256 variable
Ethereum: 000000000000000000000000d5bc1de8fa494faf0719d28db264fdce6af755eb
Polygon: 000000000000000000000000c27a32fd25e90699696dbf33c9c3d3177416d48a ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff-- This is largest 256-bit unsigned number and essentially means unlimited approval
If the contract owner sends the transaction, the scammer can transfer all the tokens that the contract owner has in his/her own wallet to any other address.